Use of the Fluoro-ProGraph-RP digital fluorograph for tomosynthesis is described. Specific conditions for application are listed, and results of its functions are presented. In particular, ...calibration of a focal spot of X-ray generator is discussed, as well as elimination of optical distortions and experimental tests for marginal effects in the case of large objects. The tests performed in this work show that the Fluoro-ProGraph-RP fluorograph can be used in tomosynthesis.
An experimental comparative study of the efficiency of three methods for measurement of the resolution of digital radiographic systems is described. An algorithm for subpixel angular projection was ...constructed. This algorithm allows the resolution of X-ray camera and test object to be measured using a narrow slit and sharp edge. Test results obtained using various methods are compared.
Tomosynthesis of an anthropomorphic head phantom using the ProGraf-7000 apparatus is discussed. The sections of the immobile head phantom were reconstructed from images obtained in the ProGraf-7000 ...apparatus using special software and system radiation source–digital matrix detector. Tomosynthesis parameters were optimized using two series of tomographic images obtained at equal anode voltages, imaging angles, and angular intervals. The series differed in exposure time (series 1 – twice-longer exposure). The tomosynthesis imaging quality was increased using additional tomosynthesis series (pixel subtraction or elimination).
Slices of density of an object reconstructed using tomosynthesis from a limited-angle projection are attractive as a medical diagnostic tool due to high resolution of such slices and much smaller, ...compared to full-angle CT, required radiation dose and cost of instrument manufacture. However, the incompleteness of the projection sets leads to reconstruction artifacts that look like smeared (or repeated) and faded images of actual objects lying in other slices and requires reconstruction methods tolerant to such incompleteness and convenient for possible use of additional information about the object for the suppression of artifacts. The reconstruction method of folded projections, which is advantageous for limited-angle projection sets, is suggested. Examples of reconstructed slices are given for scanning angles 40, 60, and 90 degrees. A specially designed plastic phantom containing metallic inclusions producing strong artifacts was used. The study of these and other reconstruction results in various geometric and noise conditions indicates that the tomosynthesis option producing images of acceptable quality can be implemented in the standard ProGraph-7000 X-ray apparatus and may have considerable area of application.
Measured and calculated doses of transmitted and reflected X ray radiation were compared. Calculated doses were obtained using the Monte Carlo program GEANT and a model of X ray radiation ...transmission/reflection. X Ray radiation load on the patient was decreased using filtering of soft (non-working) range of the X ray spectrum (<10 keV) at the output of the radiation source of the X ray apparatus. An optical model of radiation propagation through matter was considered. This model provides prompt and accurate estimates of transmitted and reflected radiation dose in case of a narrow splayed X ray beam and matter of uniform chemical composition without use of the Monte Carlo program GEANT.
This work describes specifications of a modern domestic film mammograph available from ROENTGENPROM JSC. Serial production of this mammograph began in 2008. This was the end of the first stage of ...development of a series of mammographs. The second stage included manufacture of the Mammo-RPTs digital scanning mammograph. This stage will be finished in late 2009. A biopsy unit compatible with this mammograph will be developed in 2010.
X Ray radiation dose characteristics were measured in the chamber of the ProScan 2000 chest X ray survey unit, in transparent plastic, and in a Torrance model Pelican Products (USA) human body ...phantom made of tissue equivalent rubber. Measuring conditions were simulated using the Monte Carlo GEANT program. Results of measurements were compared with model data. A method for assessment of the dose of patient radiation exposure using chest X ray survey unit detector is sug gested. The error of the measurement is estimated.
